Art of producing alloyed steels.



J. GHURGHWARD. ART OF PRODUUING ALLOYED S-TEELS.

APPLICATION FILED SEPT. 18, 1907.

- PATENTED APR. 7, 1908.

UNITED sTA T Es PATENT OFFICE.

JAMES OHURGHWARD,

OF NEW YORK, N. Y.

ART OF PRODUCING ALLOYED STEELS.

Specification of Letters Patent.

Patented April 7, 1908.

7 Application filed September 18, 1907. Serial No. 393,488.

To all whom it may concern:

Be it known that 1, JAMES CHUROHWARD, a subject of the King of Great Britain, and a resident of the city, county, and State of New York, have invented certain Im rovements in the Art of Producing A lo ed Steels, of which the following is a speci catlon.

This invention relates to certain improve ments in the art of producing alloyed steels,

'and has for its object to provide a process of a novel and simplified character whereby segregations of the allo 1 111g metals .are restored and the producing of alloyed steels of homogeneous texture andpossessed of improved physical properties'is assured.

The invention consists in a process for the productionof alloyed steels inwhich the meltin of the component metalsof the alloys steel to be produced is accomplished with relation to certain temperatures and periods of time, all as will be hereinafter fully s'et'forth.

action wherein the particles of the alloying metals are brought nto intimate union with the particles of the iron or steel stock, enter- 1 ing into and exchanging there with and forming new compound molecules or particles in which the iron or steel and alloying metals become a part and parcel of each 'other, unless'this interchange and intimate ing metals will either uniont'akes place, the alloying metals can onl become mere segregations in the mass,

an since the arenot in union the physical character of t e product is greatly impaired.

'- If the alloying metals are not brought into aproper condition, the entry and interchange can only be partial and a pJortion of the allo e carriedv by t e manganese contained in the bath to the surface, where it enters the slag, oxidizes and becomes lost, or the particles not entered of the alloying metalswill cool in the mass in f minute microscopical segregathe fo the bath sets 11 tions. As soon as the alloying metals are brought into a proper condition for entry and interchange the manganese contained in a chemical action which forces the'partic es of the alloying metals to enter and interchange and. be in intimate union with the steel or iron particles. This is the first chemicalchange after melting. Following this interchange and union there comes a period of inactivity of the alloying,

metals. The len th of this period of inac tivity is governe by the character of the alloying metals, the maximum temperature of the metal bath, and the percenta e of manganese contained in the bath. Fo lowin'g t is eriod of inactivity of the alloying metals, t ere comes a reverse chemical action whereby the molecules: or particles of iron or steel, e ect and throw out of union the par ticles of allo ing metals, the particles thus thrown out oatingor being carried up by the manganese to. the surface, where they enter the slag and are lost.

A pure metal takes longerto melt and interchange than a ferro a loy, and the bath should be governed accordingly. There are two reasons whya ferroalloy melts quicker than a pure .metal, namely; The iron of the alloy having a lower meltm point than the alloying metal, melts first, thus releasing the alloying metal in the form of minute specks, which melt readil and rapidly. The cal" bon in the ferro al oy, whenreleased, causes an artificial heat around itself, many hundreds of degrees higher than the temperature of the bath proper and this temporary-- chemical heat assists in meltin the particles or specks of the alloying meta s.

Each of the'steel alloys takes a different period of time to enterand interchange and these periods vary from 30 seconds to 30 minutes dependent on how refractory the alloying metal is. By carrying out the temperature of the metal bath from about 3100 'F. to about 3600 F. and holding it at this temperature for a period of from 15 to minutes the metal becomes in a more receptive state to interchange and enter into union with the alloyin metals than it does at a temperature be ow about 3100 F. Above about 3000 F. the metals make a better interchange and union than below about 3000 F. and the furnace losses do not amount to one halfas much.

To enable manufacturers to better understand the meaning of this invention referwe designate the retardation point of the metal bath. At this point the movement of the allogingBmetals are temporarily stopped, retarde represents the period of time during which the alloy remains asleep or inactive and which we designate the period of rest. At the end of the period of rest is the point C where the reverse chemical action commences. We designate the reversing point and the period that follows this as the period of chemical reverse action and is re resented at D on the drawing. After t e melting takes place a period occurs during which the interchange and union is being accomplished and this period ma be designated as the period of entr and mterchan e and is indicated at E on t e drawing. T e

arrows at a during the period of entry and interchange denote the alloy entering into intimate union with the stock iron or steel, and the arrows at b-during the period of reverse chemical action denote the alloying metal being ejected and thrown out by the mass molecules.

As an example to show how our invention works we will take a well known steel alloy, nickel chromium manganese. The f urnace' can be charged with percentages of Bessemer pig, nickel skullsnickel shavings-nickel turnings etc. etc. with the necessary fluxing material. With this charge the furnace may be carried to a temperature of about 3100 F. to about 360091 and after bein held at this temperature for a short perio a ercentage of manganese should be adde to recarburize the bath, cleanse the bath of gases and float u oxidations and im urities to the surface. The balance of nicke necessary to makeup the percentage required in the finished product i can now be added. The metal bath should remain at its maximum tern erature after this-addition for a period of fiom 15 'to 60 minutes, depending onthe temperature of the bath. At the expirationof this period of time the chromium can be added, with some manganese with it. From 15 to 40 minutes after this addition the furnace should be -ta ed and the heat run out into the ladle. e furnace should be tapped durin the period of rest and on no accountsho d it beallowed to go beyond the reversing point where it will enter the eriodor zone of reverse chemical action. 4 irectly the bath is carried beyond this oint losses of the refractory alloying metal ake place and these losses will be in proportion to the length of time the furnace remains untapped after the reversin point has'be'en reached and passed. If the ath is continued long enough in this zone nine-tenths of all refractory alloys will be ejected and lost. If the bath is tap ed before the retardation point is reached t e interchange and union will not have been completed and such interchange being onl partial, a portion of the refractory alloys wi 1 cool in the mass in the form of minute microscopical se regations, thus failing to impart their full va ue of force quently to the mass itself. The finished product will not have the full ph sical qualities it would have had, had the a loying metals been properly brought into intimate union with the mass molecules.

Any or all combinations of alloying metals can be successfully worked by this method, taking care that each and every one has the full eriod of time necessary for its entry and mterchange and that none are carried beyond the per1od of rest. All non-refractory metals of the nickel family can be added to the metal bath at an early stage of the heat.

bath is in a fit state to receive them and vanadium can only be added to the ladle. These temperatures and periods of time are especially valuable to thefollowing chem ical compounds, viz. nickel, chromium and manganese ;nickel, chromium, tungsten and man anese;nickel, chromium, vanadium an .manganese;nickel, chromium,

steel and steel alloys. 7

. I do not limit my invention to the use of crucibles, and the words metal bath as herein used are intended to includeall these. Having thus described my invention I claim: 1. The herein described process of producing alloyed steel which consists in melting the component metals at'a temperature of from about 3100 F. to about 3600 F.,

temperature for a period offrom 15 to 60 minutes.

ing alloyed steel which consists in melting iron or steel with a non-refractory metal at a temperature of from about 3100 F. to about 3600 F., and holding the metal bath at its maximum temperature for from 15 to 60 minutes.

3. The herein described process of produc ing alloyed steel which consists in meltin iron or steel with thealloying metals nicke and manganese at a temperature of from about 3100 F. to about 3600 F., holding the metal bath at its maximum temperature for from 15 to 60 minutes, then addlng chroniuni, or chromium and. tungsten then holdmg the metal bath for a period of from 15 to l 40 minutes at not substantially less than and holding the metal bath at its'maximum 2. The herein described process of produeand energy to the mass molecule and conse- All refractory metals must be added after the tungsten, vanadlum and manganese, and are also available for any other combination of I basic or open hearth furnaces, since the process is equally applicable to all furnaces and iron or steel with a non-refractory metal at a temperature of from about 3100 F. to about 3600 F holding the metal bath at its maximum temperature for from 15 to 60 minutes, then adding a refractory metal, then holding the metal bath for a' period of from 15 to 40 minutes at not substantially than 3000 F., and then tapping the furnace.

5. The herein described process of producing alloyed steel which consists in melting iron or steel with a non-refractory metal at a temperature of from about 3100'F., to about 3600 F., holding the metalbath at its maximum temperature for from 15 to 60 minutes,

then adding chromium and tun sten, then holding the metal bath for a perio of from 15. to 40 minutes at not substantially less than 3000 F. and then tappingthe furnace.

6. The herein described process of producing alloyed steel which consists in melting iron or steel with non-refracto alloying metals at a temperature of from a out 3100 F. to about 3600 F., holding the metal bath at its maximum temperature for a period of from 15 to 60 minutes then adding a refractory alloying metal, then holding the metal bath for a period of from '15 to minutes at not substantially less than 3000 F., then tap-' ing the furnace and running the heat out mto the ladle and then adding vanadium to the ladle.

7. The herein described process of producing alloyed steel which consists in melting iron or steel with non-refractory alloying metals at a temperature of from about 3100 F. to about 3600 F., holding the metal bath at 40 its maximum temperature for a period of from 15 to 60 minutes then adding a refractory alloying metal then holding the metal bath for a period of from 15 to 40 minutes at not substantially less than 3000 F., then tap ing the furnace and runnin the heat out mto the ladle, and then ad ing vanadium and tungsten to the ladle.

In witness whereof I have hereunto signed my name this 17th day. of September 1907, in so the presence of two subscribing witnesses.

JAMES CHURCHWARD.

Witnesses:

J. -D. CoPLmoER, F. W. WIMAN. 

